Geotripper

The sun rose on day nine of our journey down the Colorado River, into the Great Unknown, as John Wesley Powell had called it. Powell and his men had a terrifying couple of days following their discovery of Bright Angel Creek. They had lost much of their equipment in boat accidents, and their food was running seriously short. The rapids kept their pace frustratingly slow because they simply couldn't afford another accident. They portaged whenever they could, and used their ropes to lower the boats through the worst rapids. And now they were finding some of the worst rapids they had seen, rapids that filled the canyon bottom, offering few places to portage. And the rapids were big, bigger than any they had seen on their 400 mile journey. And that's where we found ourselves on this beautiful morning, facing nearly a dozen major rapids in one day, including two class 8 rapids, and a class 10, the ultimate rating.

The technology of rafting has changed and boatmen have the advantage of accurate maps and descriptions, so the rapids aren't the terrifying experience they once were. Today's rafts are better designed for running rough waters, and even when they flip, usually little equipment is lost (there are exceptions of course; I suspect a disturbing amount of equipment sits among the rocks at the bottom of a few rapids).

But the dangers couldn't be ignored. Crystal Rapid especially is a killer; at least five people have died here since 1983, and ominously, they all were men aged 54 to 66 (just guess how old I am...). Since Glen Canyon Dam was completed in 1963, the river runs very cold, in the low 50 degree range, and ironically, hypothermia can kill on a day when the temperature is over 100. The sudden shock of cold water has given people heart attacks.

But those are the bad statistics, and more than half a million people have run the rapids without dying, making running the river no more dangerous than driving on a highway (oh, wait...). We looked forward to an exhilarating day.

We scouted each of the big three rapids. I took videos of the rapids while we scouted, but no one is on rafts yet. As my brother's GoPro videos get posted, I will link to them. The ones I've seen give a nice feel for what it is like running a rapid.

It's a funny thing...if the run through a rapid goes well, it's over with in a few seconds, and the mind doesn't really have a chance to develop a distinct memory of that specific rapid. I had a bit of trouble recalling particular rapids at the end of the day unless something crazy happened, and most of our runs went well. The run through the rapid begins by floating down the smooth tongue of water at the top, and choosing whether to go straight down the wave train, or to go left or right to avoid holes, pour-overs and eddies. Those in the front of the raft usually get a soaking, and it's not always obvious which waves will do the deed. They often pop up out of nowhere. Then things settle down, and I dig into the dry bag to pull my camera out and take a shot of the receding rapid. That's Granite Rapid below, a class 8 riffle that we hit just a mile downstream of camp.

Then we scouted Hermit Rapid, another class 8 that is often described as the best roller coaster on the river, with standing waves that can be 10 feet high.

The rapids were beginning to get really fun, and with a 9 and an 8 already under our belts, my confidence level was rising. As you may have noted in previous posts, I wasn't an adrenaline junkie who went on the trip for the wild rides. Frankly the big waves scared me (literally a phobia dating from my childhood). It was hard to stand on the shoreline and look at these waves, knowing that we would voluntarily go riding on them in a few moments!

Here's the video of Hermit Rapid:

It too went well (Maybe it went "too well"?). Splashy and cold, but it was a hot day, and the water felt great (in moderation).

We regrouped at the base of Hermit and moved on through Boucher Rapid (4) without incident.

Crystal Rapid lay just two miles downstream. The river, as always, was deceptively serene and the scenery was incredible. We were still floating through the deepest parts of the Granite Gorge, and every turn of the river revealed new vistas of the 1.7 billion year old rocks. At times we could see the Paleozoic sediments far above.

We passed a fascinating exposure of the metamorphic rocks with vertical fractures that reminded me of columnar jointing.

Boatman talk of Crystal Rapid in hushed tones (how's that for a cliche?). Until 1966, Crystal Rapid was barely a riffle, a class 1 or 2 rapid that hardly merited notice. Then an unprecedented cloudburst dumped around a foot of rain in the drainage above. A huge debris flow blocked the Colorado, forming a complicated rapid with a pinball-like maze of holes and whirlpools. What's worse is the length of the rough water. It might take only moments to pull someone out of the water in most other rapids, but there is no place for the other boats to station themselves until hundreds of yards downstream.

The end of the rapid is called the Rock Garden. It contains gigantic boulders that attract rafts, hoping to trap them for a few hours. That's it in the photo below.

So here is my video of the Crystal Rapid scout. Note especially the two huge standing waves at the top of the rapid.

I could hardly foreshadow things any more than I have, but I wandered down to the shoreline where the boatman were discussing the best route through the maelstrom. The picture below that I just happened to snap shows the problem spot at the beginning of the rapid. There's a huge (huge) hole in the main channel, and a problem rock on the right. The raft needs to find a route between them. If you can't quite see it, I've annotated it below.

You can see the surging wave at 17 second in this video I took from the shoreline.
And so we hopped onto the rafts and started down the rapid. I think my boat ran third..

What happened next was not fun. And that's it for the pictures for reasons that will be clear. From my journal...

Then, oh sh*t!

We hit the edge of the hole, I saw a wall of water and suddenly I was under water and under the boat. Too shocked to think about it, I bumped on the underside of the boat for a moment, and bobbed to the surface for a moment to face another huge wave, and another. Chaos! What to do? I couldn't think so I did what I imagined I would do over and over before the trip. I couldn't see the shoreline, but I saw the boat about 10-12 feet ahead of me...started swimming as hard as I could, and first I didn't feel I was catching up, but knew I had to...6 feet, 5, 4, 3, grabbed at the line, missed, grabbed again, caught it, hung on for dear life (really dear) and started thinking what next...

They say swim with your feet downstream and don't get in front of the boat...too easy to get caught on rocks. Of course the boat twisted and put me in front...I went hand over hand, past a hanging bucket so I was alongside, feet trailing behind me. Then I hit the Rock Garden and bounced off a few boulders on my behind, but I also found a handle on the boat. The turbulent waves finally ended and I was able to see that Barry and Bev were trying to get to me.

They pulled alongside and I was too tired to kick my way onto their boat (note: I had been in the frigid water for four minutes already, and it was starting to affect my ability to swim). Jeff jumped over to their boat and they were able to pull me in.

I could only sit and breath for the next 10-15 minutes while they wrangled the flipped boat. Pete was okay, he swam ashore near the top of the rapid (note: as I wished I had done).

We had ultimately traveled 1/2-2/3 miles downstream, almost reaching the next rapid (which would have been a deadly outcome for someone in the water, due to hypothermia alone). We got everyone together and flipped the boat back to its proper orientation, then moved a short distance downriver to a beach where we had lunch and where I could collect my wits. I was unhurt despite bouncing off the boulders, and I quickly recovered from the frigid dunking in the hot sun. I was most disturbed by how my life vest rode up my chest and almost came off when they pulled me on the boat. Some have suggested that now that many passengers on the river these days are...um...kind of pear-shaped like me that life vests need a strap between the legs to prevent them from slipping off in emergencies. I tend to agree.

We assessed the damage. No major equipment missing (it had all been strapped down), but we lost a guidebook (but had a spare). My dry bag with my camera had leaked, and the camera was not working. The thought of losing the 1,400 pictures I had taken broke my heart, and it took a few days to find out that they were okay. And...I had thought to bring a spare camera! The pictures would continue. My journal was soaked. I was able to carefully separate the pages and start drying them off. The red ink had run and was nearly unreadable, but the blue ink was okay and I've recovered 85% of my notes. Pete felt terrible about it all, but really, it was a matter of a few inches on the side of a hole in the worst (or second worst) rapid on the river.

We had eight more rapids to go through that afternoon. We made it without incident. Mentally I was okay, and really I had to be, although it was one of the closest shaves with mortality that I've ever experienced. There aren't many alternatives to continuing down the river. The steaks we had for dinner were pretty much the most delicious delectable culinary objects I had ever tasted in my life.

During the early evening, my brother's tent blew away in the wind. We never found it!

If you've been following the story so far, you will know that we reached day nine on our rafting journey through the Grand Canyon, and that day nine was a bit of a disaster for yours truly. Our raft had flipped in Crystal Rapid, the worst rapid on the river, and I took a very long swim in frigid turbulent water before being plucked out by my guardian angels (Barry, Bev and Jeff). We made it through eight more rapids that day without incident, and made camp at a narrow strip of sand called Hotauta.

As I noted in the previous post, my camera was badly damaged (I had a spare in storage), and my trip journal was soaked. I spent the evening carefully separating and drying the pages, hoping that I could recover most of them. I also had to deal with the psychological aftermath. Being in an unexpected ride down a violent river without my boat might be an expected part of river running (and certainly no one was saying it was an easy thing to do), but I'm a desk-bound professor most of the time. This was something very new for me.

The best thing I could imagine would be to have a peaceful and serene day on the river, and the Colorado seemed to understand this: there were ten rapids in our path on day 10, but only one of them, Walthenberg (6) was greater than 5 on the rapids rating scale. And it came early in the day. We had three excursions planned in the side canyons, and they sounded like wonderful places.

It seemed a good sign to have a big Swallowtail Butterfly land on my gear as we were loading the rafts. It seemed a bit disappointed that my bag wasn't the biggest darn flower ever, but it hung around long enough to get a picture.

We went through the first two rapids, Bass and Shinumo, and pulled out at Shinumo Creek.

The walk was short, but quite interesting, as the creek filled the canyon bottom. I was absolutely sure I was going to slip on the muddy rocks and destroy my remaining camera. But it was just beautiful, and the fifteen foot waterfall was a refreshing retreat from the hot sun.

We headed back onto the river, and soon passed the creatively named 113 Mile Rock, an outcrop of schist that practically blocked the river. It also marked the halfway point in our 226 mile trip (it was day 10 of 16, so our average daily mileage was going to increase).

Since Walthenberg Rapid, we had been traveling through the oldest rocks to be found anywhere in the Grand Canyon region: the Elves Chasm Gneiss, dated at 1.84 billion years. These rocks may represent the ancient crust on which the other metamorphic rocks were emplaced many tens of millions of years later. I hate to say it, but I was distracted that day and didn't realize that we were passing through these rocks until a day or two later when I retrieved my geologic map out of the luggage. But I managed to snap a number of pictures because the rocks were intriguing to look at whether I knew their age or not.

In many places the rocks are intruded by pink dikes and veins of granite pegmatite, a rock with exceedingly large crystals of feldspar, quartz, and muscovite mica (above). In a few places I could make out darker intrusions that looked like basalt (which is youngest in the picture below: the black or the light colored intrusions?)

Before Glen Canyon dam was built the Colorado River carried an incredible amount of silt and mud. According to some sources, when the river used to run at 100,000 cubic feet per second, half of what flowed down the river was sediment (Death in the Grand Canyon by Ghiglieri and Myers). The sediment gives the river the tools needed to sculpt the incredibly hard rock, and we passed numerous beautiful exposures of intricately shaped gneiss, schist and granite.

We were still in the Granite Gorge, but we noticed that the inner canyon wasn't as deep as it had been, and we started to see Tapeats Sandstone in the cliffs not too far above us.

As we neared Elves Chasm, the Tapeats was at river level, and we were treated to an exposure of the Monument Monocline in the sandstone layers. A monocline is a fold in the rocks that looks like a carpet thrown over a step: level horizontal rock, then a flexure as the rock bends downward, and then horizontal layers again. They tend to occur when a fault fractures harder rocks at depth, but only bends the sedimentary layers above.

The folds were an unexpected sight. So were the travertine deposits that were exposed along three miles of the river starting at Mile 116. Travertine is generally composed of calcium carbonate (the mineral calcite) which was leached out of the overlying Redwall, Temple Butte, and Muav formations and deposited by springs in the Bright Angel Shale. The travertine completely covered the Tapeats in places, including the area around Elves Chasm.

What is this "Elves Chasm" that I keep mentioning? It was our next stop, but that will be in the next post!

It's so hard to imagine the tourist who drives for hours and hours, arrives at the rim of the Grand Canyon, looks down and simply leaves. A person can be impressed with the huge gorge, the beautiful colors, and may even appreciate the incredible geologic story they read in the visitor center. But it sort of ends, and they move on to other things. The schedule must be maintained. The curiosity is awakened for a moment, but then it slumbers again. When do we lose the desire to yearn after greater knowledge?

Watch a child in the outdoors sometime (I know, an increasingly rare situation). A trickle of water will fascinate them for hours, and they'll pick up pebble after pebble. Leaves and bugs. Frogs. They'll play with the tadpoles. And they'll ask questions. So many questions! What is it that drives that fascination with nature out of their lives?

Standing on the edge of the Grand Canyon makes me feel like a child all over again. Maybe a child of the Cosmos. I don't want to leave; I want to explore the folds in the rock, the dark mysterious canyons. I want to float down the big river hidden in the depths below. And then it happened!

I went into the Great Unknown as John Wesley Powell called it. 226 miles over 16 days, drifting with the slow currents, and making headlong rushes down the 160 or so rapids, including a pretty good dunking at Mile 99. There was no way we could stop at every side canyon and explore, despite my intense desire to do so. I've been around long enough that I have to be a lot more careful than I used to be jumping from boulder to boulder, or climbing around on exposed cliff sides. But there were many beautiful hidden places that we did stop and explore. Shinumo Creek on the morning of day 10 was one of them. Later in the day we reached two more, Elve's Chasm and Blacktail Canyon.

As I've said many times as I've written about this trip, the canyon constantly changes. There was always something new to see and experience. Elve's Chasm was such a new place. It is a tributary canyon to the Colorado River, like hundreds of others, but in this particular spot travertine spring deposits covered much of the sedimentary rock. The creek (and debris flows) cut down through the solid rock, but then the springs flowed and mineral deposits (mostly calcite) developed and covered the rocks.

The travertine is a porous rock (as can be seen above), but it is also strong and easily cut. I was much to surprised to find that the massive columns surrounding St. Peter's Square at the Vatican in Rome (and many other building facings) were carved from travertine rather than marble.

It was bit of a climb up the canyon, but the waterfall at the end of our walk was wonderful. The fallen boulders made for easy climbing in the darkness behind the waterfall, so the kid in me delighted in climbing and then jumping into the deep pool below! Being a kid doesn't involve just asking questions...

I saw multitudes of reptiles and amphibians over the course of the trip, and once in awhile one would stay in place long enough for a picture. Anyone want to identify the species for me?

As we drifted down the river we passed a massive travertine deposit that could have been a statue of Jabba the Hut. I don't know why we need to make these natural features into something more familiar, but it happens. I guess it helps us to remember them more easily.

We stopped for lunch at the imaginatively named Mile 117.6 Camp. As we were wrapping up, we had a treat. I had seen a bighorn sheep along the river on the second day out, but had no chance for a picture (we were at the very top of a big rapid). Someone in the group spotted movement across the river, and we realized there was a herd of bighorns coming down to the river for a drink.

It was a number of ewes and their lambs. It was a sight watching them climb along the cliffs and rocks. They made me feel positively clumsy.

Even the young ones looked supremely confident. The bighorns were hunted by the Ancestral Puebloans, but I find it hard to accept that they were a major food staple. It seems like they would be a difficult prey. Powell's men had rifles, intending to supplement their diet with sheep and deer, but it almost never worked out. The sheep were simply too cautious and quick.

And hard to see! How many sheep are in the picture below?

I wondered if the sheep ever swim across the river. This didn't answer the question for sure, but a short distance downstream there was a handsome ram all by himself. I have no idea if it was his harem on the other side, but then on the other hand, maybe the ewes swam across to get away from him!

Downstream we pulled out for one more excursion up a tributary stream, this time at Blacktail Canyon. It is a narrow gorge cut through the Tapeats Sandstone of Cambrian age (around 520 million years), and a bit of the underlying metamorphic rocks of the Granite Gorge Metamorphic Suite (mostly about 1.7 billion years old).

The ledges of Tapeats contain layers of sandstone and conglomerate that represent the coastal rivers and beach deposits of the transgressing Cambrian sea that eventually covered much of the early North American Continent. As we walked up the canyon, an extraordinary contact became visible.

It was a wonderful exposure of the Great Unconformity, the buried erosion surface representing a gap in time of 1.2 billion years. We had seen the unconformity in several places along the river upstream, but it was often hidden by debris and fallen rocks, or was too high above the river to get a close look. Here in Blacktail, one can put a finger on a line representing more time than the entire existence of complex life forms on planet Earth.

The canyon had another virtue. It was a wonderful acoustic chamber. Our crew brought a harmonica, but they told stories of others who have brought brass instruments or cellos to make beautiful music. As Pete played a song, a canyon wren added a counter melody that just made my heart soar (you can scroll down this page to hear a canyon wren). I love those birds !

At the head of the canyon, we found a pool and a small tricking waterfall. It was such a peaceful place to explore. As everyone wandered back down the canyon I sang a few verses of "Amazing Grace". I was still upset by the rough ride down the rapid the previous day. I had profusely thanked the wonderful people who were there to pull me out of the turbulent water, but thought it would be nice to send another message into the Cosmos to whomever might be listening.

Through many dangers, toils and snares
I have already come;
'Tis Grace that brought me safe thus far
and Grace will lead me home.

We headed down the canyon and back onto the river. We reached a sandy camp called Enfilada. Interesting things lay ahead down the river, and the boatmen were beginning to talk about Lava Falls.

Every day is new. Every day the Canyon is different...

I look back over the notes of my journey down into the Great Unknown, the Colorado River through the Grand Canyon, and I am struck by the number of times I mention change. By mile 80 we had passed through essentially all the major rock units of the Grand Canyon, and one can be forgiven for thinking that things might get repetitious, but it just never happened. I was now fifty miles farther downstream, and every morning, every day produced new revelations. I knew by now on Day 11 that I was having one of the most incredible experiences I would ever have in my life, and still five days remained.

The day began as a sort of "passages" kind of journey. We needed to make 15 miles or so, and there was just one excursion up a side canyon in the plan. But there were also some big rapids to worry about, including Specter, Bedrock, and Deubendorff, as well as seven smaller ones. I could tell I was still a bit spooked after my swim down Crystal Rapid a few days earlier.

Enfilade Camp was on a sandy beach below a large terrace that promised a decent view. My nephew had hiked up the previous evening and had come face to face with a bighorn ram, so I was a bit curious to see what would be around in the morning. I found a nice view upstream and downstream, and a lot of sheep tracks and droppings, but none of them were visible (of course, given their excellent camouflage, they were probably there watching me).

We started the day in the Bright Angel Shale of Cambrian age, but before long we entered into the Granite Gorge again. It's interesting how we refer to the "Granite Gorge" when so much of it is actually composed of black schist. I was just stunned by the polished surfaces that looked all the world like obsidian, even on slopes dozens of feet above the river.

The canyon walls closed in once again, and the schist cliffs rose high above us.

In eleven days we had dropped 1,200 feet or more, and the flora was picking up a definite Mojave-Sonoran flavor. Barrel cacti were common on the slopes above the river. Within a day or so we would be seeing ocotillo.

We reached Bedrock Rapid (6-8) and stopped to scout. It was appropriately named, as a big chunk of granite and schist split the river. If a boat went to the left, it would be caught in a too-small current and impossible eddy. But the river right tried to dash the boats against the rock outcrops. It took some hard rowing, but the boatmen got us through just fine. We bounced off a boulder, but it was done quickly and we were okay.

The river at Bedrock Rapid tries to mash my brother and sister-in-law against a cliff. I give them credit for carefully observing the geology.

Below the rapid I saw one of those extraordinary sights that seem to occur with continuing regularity. I've mentioned the Great Unconformity, and we saw a wonderful exposure in Blacktail Canyon, described in the previous post. The ancient erosion surface separates 500 million year old sediments from 1.7 billion year old metamorphic rocks. It is marvelous to be able to lay one's hands on 1.2 billion years of missing history.

But the canyon hides secrets, and one of them is that rocks exist that fill that void. There are in fact lots of rocks, in layers about 12,000 feet thick. We had visited them earlier in the trip, in the area between Nankoweap and Hance Rapid. They too rest on a "great unconformity" spanning 500 million years. They in turn are overlain by the Tapeats Sandstone. Because the Supergroup has been tilted, they contact the rocks above at an angle, so this contact is known as an angular unconformity.

Above Bedrock Rapids, both unconformities could be seen in the same outcrop! The sun was at a difficult angle, so if you can't see it, take a look at the labeled version below. I've drawn this kind of rock relationship on chalkboards many, many times, but I haven't seen as many of them in the real world.

Downstream we encountered Deubendorff Rapid (5-8). As we bulled our way through, we caught the edge of a hole and lost an oar. Pete worked with the remaining oar, but got us through okay, if not a bit soaked.

Drifting along the river below, we encountered the second extraordinary sight of the day. Dikes and sills are the result of molten material forcing its way through solid rock. Dikes cut across the previously existing rock, while sills squeeze their way between layers. You can see examples of dikes, but few sills on my Geotripper Images website, and that's the thing: I don't have many pictures of sills.

As we came around the bend of the river, a black cliff came into view, a layer that ran parallel to the enclosing layers of Bass Limestone and Hotauta Conglomerate (these form the base of the Grand Canyon Supergroup). It was a basaltic sill of huge proportions. The precise name of the rock is diabase, which was a shallow intrusion that was neither extrusive in texture (fine-grained) or intrusive (coarse-grained). It's a grain-size in-betweener.

It was one more stunning sight in a canyon with many of them.

Soon after, the river re-entered exposures of the Granite Gorge Intrusive Suite, and the canyon narrowed. A lot. The walls of schist rose straight out of the river and soared for hundreds of feet. Just past Mile 135 we traveled through the narrowest gorge in the entire Grand Canyon, the Granite Narrows. It was only 76 feet wide. The river was over 100 feet deep!

It had been an incredible day, but the best part was just ahead. More on that in the next post!

We continued down the Colorado River, the "Great Unknown" as it was called by John Wesley Powell during the first boat trip through the Grand Canyon in 1869. In the last post, I mentioned that we passed through the narrowest channel in the entire canyon, a spot in the Granite Narrows where the river is 76 feet across and more than 100 feet deep. I didn't mention why this spot just happened to be so narrow. The story of how it got this way touches on our next pull-out at Deer Canyon Falls, and on Yosemite Falls in a totally different national park back in my home state.

In my youth, I used to drive up San Antonio Canyon in the San Gabriel Mountains, and my poor little VW Bug had trouble surmounting a big ridge called the Hogback. It was a gigantic rockslide that had forced the creek into the cliff, where the river was forced to erode a granite slot canyon in an otherwise debris-filled floodplain.

I found out that the narrowest channel in the Grand Canyon formed in much the same way! It turns out that if you stack thousands of feet of sediments onto a plain that then rises to become a plateau, and carve a deep canyon into it, it will turn out that some layers will fail due to the weakness of the rock and form gigantic rotational slides. At Granite Narrows these large rotated blocks blocked the flow of the Colorado, forming a temporary dam and causing the river to establish a new channel in the hard rocks of the Granite Gorge Metamorphic Suite. Because the channel is newer, it has not had time to widen as much as older parts of the canyon.

The picture above shows the Granite Narrows from the vicinity of Deer Creek Falls, with a portion of the Surprise Valley slide on the left side above the river. It also turns out that the landslides in the area had another unexpected result.

Deer Creek Falls sits at or near the top of a list of the most beautiful sights along the Colorado River in the Grand Canyon. The creek seems to burst out of the canyon wall, falling a hundred feet or so onto the river shore (during periods of highest flooding, the waterfall tumbles directly into the Colorado). It was truly a stunning sight as it became visible around a turn in the river. We pulled out to have a closer look.

We took the very steep and hot trail that climbed out of the Granite Gorge and into the Tapeats Sandstone where Deer Creek has carved what may be the most incredible narrows in Grand Canyon.

The trail clings to a ledge midway up the cliff in the narrows, and it includes a couple of hair-raising steps around protruding rocks (it's on the right side in the picture below). A slip here would incur a very uncomfortable drop of 50 feet or more.

As you make your way up the gorge, it begins to dawn on you that this canyon is very narrow compared to others in the Inner Canyon, despite the rather high permanent flow of Deer Creek (the creek is fed by a large spring complex just upstream). A relatively large stream like Deer Creek ought to have been able to erode a much wider canyon. Even stranger is the relative lack of erosion at the falls. Shouldn't a stream like Deer Creek be able to erode at least some of the way through the hard metamorphic rocks? Literally every other tributary canyon has managed to do so.

The narrows are just gorgeous. I had seen a picture of them in a book when I was a teenager, and I had been wishing to hike them in real life for a long time. I was in a sort of walking dream just being there.

We could hear the water pouring through the canyon below us, but it took awhile before we could actually see it.

The canyon started to open up a bit, and we could see cottonwood trees upstream. We were reaching the top of the Tapeats Sandstone and the lower reaches of the Bright Angel Shale.

The creek was at trail level. Soaking and splashing time! It was a hot day and a hot hike...

I later came to realize what should have been obvious. The narrows were there because Deer Creek was younger than the other tributaries along the Colorado. Deer Creek Falls are there for the same reason. The canyon hasn't existed as long as the others. But why?

It boils down to the same reason that the canyon is so narrow just upstream. Landslides (slope failures) filled the ancestral Deer Creek Canyon, forcing the stream into a new channel. The diversion happened recently enough that the creek has only carved through the relatively soft Tapeats Sandstone, and hasn't really begun carving into the harder metamorphic rocks.

So it turns out that one of the most beautiful places in the Grand Canyon was the result of failure. A giant slope failure. Mass wasting, a term that encompasses all of the different kinds of slope failures and landslides, was a main tool in the carving of the Grand Canyon. The Colorado River cut downwards, while mass wasting widened the gorge, as it is still doing today.

What does this have to do with Yosemite Falls out in California? Like Deer Creek Falls, Yosemite Falls looks too "young". Yosemite Creek has not carved much of a channel at the top of the falls, which spill over a 1,425 foot high vertical cliff. It turns out that the present day falls are young, too, the result of an Ice Age glacier that diverted and blocked the old Yosemite Creek channel. You can see the older channel to the left of the modern-day falls in the picture below. It is the route of the Yosemite Falls trail today.

After our incredible journey through the narrows of Deer Creek, we got back on the river and rode through Doris Rapid. Although only rated class 3, it was the splashiest ride in a few days. We set up camp at the base of the rapid. Under a steep overhanging cliff...

Lava Falls Rapid was two days away....

Morning dawned on our crew at Doris Camp on Mile 138 of our rafting journey through the Grand Canyon, a trip I've been calling "Into the Great Unknown". The river was known well enough to our boatmen, but as I've pointed out, this was my first trip, and so I had a heck of a time keeping the geography straight. We had reached day 12 of a 16 day trip, and still had 90 miles to go. We needed to make up for some leisurely days during the previous week. The plan for the day: 27 miles, our longest day of all. We intended to camp at Tuckup.

Doris was one of the most unique camps of our trip, with a narrow strip of sand hugging the base of a high overhanging cliff of Tapeats Sandstone (both of the above pictures). After all the concentration on slope failures in the previous post, I'm glad to report there were no rock falls during the night. I did keep my eye on one precariously perched barrel cactus right over the cooking area. It stayed put.

The character of the river changed once again. We had left behind the rugged cliffs of the Granite Gorge, and had "climbed" back into the lower Paleozoic sediments: the Tapeats, Bright Angel and Muav strata. We hadn't actually "climbed", although I was ready to believe that the river was capable of just about anything. Instead, the rocks were gently folded and inclined to bring the Paleozoic sediments to a lower elevation. We had reached the beginning of a 40 mile stretch of the river called the Muav Gorge.

I was reminded somewhat of Marble Canyon, a fond memory, although the cliffs in this stretched towered a few thousand feet higher than those at Marble. Mercifully enough the river had only one worrisome rapid, Upset, which is rated between 3 and 8 depending on flow conditions. Among the other ten rapids, none rated higher than a four.

Much of the day involved floating through placid waters in deep and often shaded canyons. I was enjoying myself immensely. Pete of course had to row through the placid canyons, sometimes against the wind. His opinion may differ!

We had just one major side canyon to explore on this day, with a name I was having trouble getting straight. It is called Mad Cat Amoeba, or at least that's just what I kept hearing when anyone said the name over the course of the morning. They were talking about Matkatamiba Canyon, which is a favorite of the boatmen. They had been talking about it for the last day or two.

There were a couple of problems. The canyon entrance is right at the top of a rapid, a sort of "you have one chance to get it right" kind of docking situation. And the docking spot is a narrow pool (no beach), so the boats have to be lashed together to hold them in place. The canyon is an extremely popular stop, and we had to hope no one was there. As it turned out a big group was leaving just as we pulled up.

Another potential problem is flash flooding, which we didn't need to fret about, but you can see what happened here in 2011 at this website: http://www.youtube.com/watch?v=yi1k9dvXjXY. Some of their boats were ripped loose and drifted downstream, while others got stacked on top of each other, with a loss of some supplies to the currents of the river.

There are two ways to get into the pleasant upper canyon: walk right up the narrows and do some rock climbing, or take the high rocky trail and...do some climbing. Both choices are visible in the picture above. I took the high road...

I arrived at the "Patio", a large amphitheater-like place deep in the shade (it was a very hot day). A pleasant clear trickle of water was flowing down the canyon. After all the grand vistas of the previous 12 days, I was starting to focus on the little things, like reflections on the water.

There seem to be few things more precious than water flowing through an intensely arid desert. The heat just accented the coolness of the shadows and the sound of the splashing stream.

I spent some time on hands and knees looking for some of my shots.

The upper canyon beckoned, and I started that way, but it opened up into the blazing sun, and became much more rocky. There have been fairly recent flooding events. I turned back into the cool shadows.

It was a thoroughly pleasant visit, and I didn't really want to get back on the rafts just yet, but we had a lot of miles to go on this particular day.

When gazing at these steep cliffs and canyons, we sometimes make comparisons to cathedrals. The analogy is faulty. No human-built cathedral can match a canyon crafted by the gods.

We got back on the river for a few miles and then we took a lunch break at Ledges Camp and spent some more pleasant moments on the eroded benches of Muav Limestone.

We were approaching the mouth of Havasu Canyon and for a few moments we had a view of Mt. Sinyella, a peak sacred to the nearby Havasupai people (below). We just plain didn't have the time to explore Havasu Canyon, but the blue-green water looked inviting.

We moved down the canyon through the serene gorges. Upset Rapid required a scout, which I found made me apprehensive. We punched our way through the waves with no problems.

The reflections on the water were mesmerizing. It was a beautiful stretch of canyon.

We got to our expected camp and found it occupied by a large group already, so a 27 mile day turned into a 29 mile day. We reached the large barren campsite located at the base of National Canyon. We were beat (Pete rowed 26 miles, while I rowed just two or three miles). The boatmen were talking about Lava Falls Rapid again. It now loomed ahead of us; it was one day away...I didn't really sleep well, but the Milky Way was gorgeous.

Yeah, I was not feeling all that comfortable. It was day 13 on our journey into the Great Unknown, the Colorado River through the Grand Canyon. Day 13, and Lava Falls Rapid, the worst rated rapid on the river was...13 miles downstream. And I didn't know it yet, but we would arrive there at 13:00 hours. I'm not at all superstitious, but it was nice when the message written in the sands of time on the river shore appeared. Okay, I put it there myself, but I was apprehensive just the same!

We were camped at the mouth of National Canyon, which for many years was one of the larger and more popular campsites on the river. And then in the summer of 2012 it was hit by an apocalyptic flash flood that just about wiped the camp out of existence.

It's hard to imagine the scale of the flood. Estimates put the flow at 15,000 cubic feet per second. To put that into perspective, the flow of the entire Colorado River for most of our journey was around 8,000 to 12,000 cfs. And the flood was witnessed. A Western Rivers Expedition boat was passing by, and captured the flood entering the Colorado. Check out the video below by Joe Clark, one of the river guides:

Our campsite was rocky, but we found places to sleep. The rocky plain was barren of plant life. There is hope that a few artificial floods may ultimately deposit more sand on top of the bouldery deposits, but I wonder if the Bureau of Reclamation will be doing any artificial floods in light of the ongoing drought.

In any case, the experienced members of our crew were curious about how much the canyon above the river had been changed by the flooding. To me, the canyon was a beautiful place, regardless of how it might have once looked. How could I know any difference?

I could see that eroded ledges of Muav Limestone had indeed been buried in debris, and barely a single plant was visible along the course of the creek, despite the presence of a clear babbling stream. The going was tough in a few places. Boulders choked the channel.

The barren nature of the canyon was almost disturbing. It felt like there should be plants growing along the water. It drove home the point that no matter what ever else may happen, the rocks remain. Battered, broken, or polished smooth, they will last as everything else passes. But the rocks were also very beautiful, though, and the narrows spectacular. It occurred to me that this canyon, were it to be anywhere else in the country would be a national park or monument in its own right. Here, it was simply a tributary to the larger river, one of many.

The sun was high, and it was getting hot. We got onto the river and rowed downstream. We had reached a fairly long stretch with no major rapids, and lots of quiet passages through vertical canyon walls of Paleozoic sediments. In places we could see all the way to the canyon rim four or five thousand feet above us. The rim, and the world beyond, seemed remote and very far away.

I did a double take at Mile 176. Thousands of years ago massive landslide had broken away from the Supai cliffs out of sight above, and had come thundering over the Redwall Limestone, coming to rest near the river. It is called the Red Slide.

Over time erosion began to tear away at the debris-covered slopes, but here and there a large boulder protected the underlying soft material. The boulders were left standing on spires called hoodoos. It was yet another strange sight along the river.

I was on the lookout, because for the first time we would be seeing a new rock unit (the last "new" rock unit had been 100 miles upstream). It is not a familiar rock to the vast majority of visitors to the Grand Canyon, and in fact, most people are surprised to find out that such rocks are present in the national park: there are volcanoes and lava flows!

I looked high on the walls, and there was the first one, a fragment of black basalt clinging to the cliff. It was an exciting moment for me, because I've never seen these rocks before. I will deal with the profound effects of the lava flows in one of the next posts.

There were more signs of volcanism along the river where a sill had intruded into the Muav Limestone. It was one of the finer examples I've ever been able to photograph.

Soon we could see the source of some of the lava flows, a cinder cone on the high canyon rim called Vulcan's Throne.

We could also see the long tongue of lava from Vulcan's Throne that had reached the river. John Wesley Powell's description remains one of his most poetic writings:

Just over the fall a cinder cone, or extinct volcano, stands on the very brink of the canyon. What a conflict of water and fire there must have been here! Just imagine a river of molten rock running down into a river of melted snow. What seething and boiling of the waters; what clouds of steam rolled into the heavens!

And then, one of the strangest sights of all. A huge mass of congealed lava stuck right in the middle of the river. It was a plug of lava that filled the vent of one of the cinder cones. Called Vulcan's Anvil, it seemed like a message or a warning to river travelers, which indeed it is.

When we passed the anvil, we know we had less than a mile to one of the biggest challenges on the river: Lava Falls Rapid. The moment of truth had arrived...

The Anvil receded into the distance, and we prepared to scout the wildest rapid on a wild river.

I was going to title this post about our trip into the Great Unknown "Courage, Redemption, and the Triumph of the Human Spirit at Lava Falls: Geotripper Rides the Big Rapid", but I knew my fellow travelers would all yell "Bullschist" in four-part harmony like the townspeople in Blazing Saddles. So we'll settle with what I put up up above for a title.

Still, the oarsmen have a saying: "You don't f*ck around with four rapids in the Grand Canyon, Hance, Horn (or Granite? I don't always listen well), Crystal, and Lava Falls". And they were right. I took a long and harrowing swim in Crystal Rapid several days earlier, and I wasn't anxious to do such a thing again. For several days now, the oarsmen in our group had been talking about Lava Falls, and now having passed the massive volcanic plug of Vulcan's Anvil, we were at the top of the worst rapid on the Colorado River, and one of the toughest rapids in North America. It is rated at Class 10 out of 10 on the river runners scale.

Really, how many rapids rate a 90 page geological analysis? You can see it right here: http://pubs.usgs.gov/pp/1591/report.pdf .

A quote from the ever-staid and formal geological investigators:

Lava Falls, at river mile 179.4 on the Colorado River in Grand Canyon, is one of the most
difficult navigable rapids in the continental United States and is the standard against which all rapids in Grand Canyon National Park are judged for navigability.

I had been thinking about Lava Falls a lot over the last couple of days, and after my dunking in Crystal Rapid, I was pretty sure I would elect to walk around the rapid. Looking at my journal, I see that I even said so twice in the days leading up to our arrival. Still, I told myself that I would take a look and consider it.

Two very strange things happened to me when I climbed up to the scouting ledge at the top of the rapid. First, I didn't panic. It made a difference actually seeing the rapid, in contrast to thinking and pondering on the idea of a monster rapid. Somehow the analytical part of my mind was looking at the rapid and picking out the possible route through the pinball arrangement of holes, rocks and ledges, and it managed to suppress the urge of the other part of my brain to run down the talus slope and await the arrival of the broken boats and injured bodies of my comrades at the base of the rapids. I even managed to see the route we needed to follow through the rapid (confirmed a moment later as I listened in on the discussion taking place between the oarsmen). Where would you go, looking at the picture above? Take a guess, and then look at the photo below...

The second very strange thing that happened was that I experienced a Hitchcockian case of vertigo every time I looked at the rapid. The whole scene swam in front of me whenever I looked at the waves. I've never had vertigo in my life, and didn't even know what to call it at the time, but I would look away to the cliffs above, and no problem. I'd look at the river again, and it would start wavering and swimming in front of me. As best as I can figure, the reptilian core of my brain was desperately trying to overcome the analytical part of my brain and toss it into the river so I would do the safe thing and walk around the rapid.

Why is Lava Falls such a treacherous rapid?

All the rapids on the Colorado River in the Grand Canyon exist because of debris flows. These floods of giant boulders and mud emerge from the tributary canyons and pile into the river, pushing the flow into a narrow channel on one side or the other. The river has to speed up as it passes through the constriction, and it drops anywhere from a few feet to as many as 30. The severity of the rapid is determined by the length of the rapid, the drop, and the arrangement of large boulders along the way. The level of the Colorado River is also an important consideration. Some rapids are better if the flow is higher. Others are better at low flows.

Lava Falls formed because of debris flows that emerged from nearby Prospect Canyon. During intense cloudbursts, water pours down the cliffs of the Supai Group and overlying Permian formations, and drops over a 1,000 foot cliff of Redwall Limestone. The waterfall hits the slope debris at the base of the cliff, and forms the debris flow via what the researchers call the "firehose effect". The deposits along the river record a great many flooding events over the last 3,000 years. One of the prehistoric events dammed the river to a depth of nearly 100 feet. The rapid formed by that event would have dwarfed the present-day Lava Falls. More recent debris flows altered the rapid in 1939, 1954, 1955, 1963, 1966, and 1995. The 1939 event was the largest historical debris flow in the modern history of the Grand Canyon, larger even than the 1966 event that turned Crystal Rapid into such a monster. The flow was estimated at 35,000 cubic feet per second. That would be considered a high flow on the main Colorado River. The pile of debris constricted the river to only 20% of its normal width for a time (about 50% today). Lava Falls had become a monster rapid.

Lava Falls Rapid has a gigantic ledge at the top that forms a huge standing wave that can trap a small raft for hours. Routes can be possible on both the right side and left, but the left side has large boulders that can trap boats near the base of the rapids. High flows can diminish the danger. Most runs occur on the right, but there is another huge hole and standing wave that must be avoided on the far right side. Boats have to punch through the huge V wave, avoid the huge boulder called the Cheese Grater, and then navigate past two other gigantic waves, the Kahunas. It's the worst rapid, but short. The whole ride lasts less than 20 seconds if done right. Done wrong, and you'll be pitched into the water for a wild ride, or caught on a boulder for hours (see an interesting story about one such trapped boat right here).

Let's see what a good run through Lava Falls looks like. Ron was one of the most unflappable oarsmen I've ever seen, and here he can be seen taking Lisa and my nephew Samuel through Lava Falls. He catches the right side of the ledge above...

They punch through the V wave...

They nearly get swamped by the gigantic Kahuna Waves while simultaneously avoiding the Cheese Grater on the right...

And they make it through, wet but unscathed!

My brother Mark and his wife Carol are guided through by their oarsman Gerrish, and even though their boat was oriented almost 90 degrees, they made it through too.

Mark took a GoPro cam so you can watch the ride from his point of view right here:

Meanwhile, I was still up on the scout rock watching my brother's family running the rapids. The moment of truth had come and someone behind me asked if I was going to ride the rapid. A disembodied voice quite separate from my conscious mind said "yes". I wasn't sure who spoke, but since everyone was looking at me, I guess it had been me. I don't know what I was thinking... I pulled Pete, on whose boat I was riding, off to the side and said to him "I need an honest answer...is it better if I'm in the boat (extra weight, lots of it), or not?" He said he needed the weight to help punch through the waves, so I was going.

We got in the boat, and this time the camera and the journal were stowed as tightly and securely as possible. I wasn't going to lose a second camera, and the loss of my journal would have been devastating. I hunkered down in the front of the raft and we pushed off.

A story of redemption and courage would end with a victorious run through the rapid, and a confirmation that it is always better to bravely face your fears. Always get back on the horse after you are thrown. Jump back into the battle after your nose has been bloodied. The story ends with an affirmation of the human spirit, and a slow motion montage of arms thrown in the air in victory. That's how the movie script would end. Here's what actually happened, courtesy of Bruce Burger who was shooting our ride from the scouting rock (his effort to get the movie posted is greatly appreciated!):

Yup, we flipped on the V wave. Personally I don't think anything was wrong with our approach. Our boat was just too short and too lightly loaded, and we simply caught the edge of an unlucky wave. In any case, I was in the water again. It was a shock, but it was far less terrifying this time around. I bobbed up quickly and the boat was right there. I grabbed on, and once again I realized I was in front and headed towards being crushed against the Cheese Grater. I quickly shifted to the side of the boat, but the current shifted left, so we missed the big rock. We rode out the two Kahuna Waves and the river quickly settled down. I was in calm water within a minute or less.

I found out that Pete had a worse time of it, because he got trapped under the boat briefly, and tumbled head over heels in the dark water. That had to be a horrific ten seconds (and seriously, they would have been the longest ten seconds of anyone's life), but by the time I was able to check behind me he was swimming too.

Once again, Barry and Bev came to the rescue, and since I had only been in the water for two minutes or so (and being a hundred miles downstream the water was not quite as cold as before), I was able to help climb onto their boat, and I was even able to be an active participant in catching our overturned raft. We got the boat flipped back, and the only losses were my rowing gloves and my hat (I had a spare). The camera was safe, and a few moments later I snapped a self-portrait of the not quite drowned river rat.

And that was that. We had survived the greatest rapid on the river. It's hard to say if I should have walked. I feel good about facing the challenge and being part of the team, but I also just a bit more nervous every time a medium to large rapid loomed. But for the rest of the trip there were only a few, and I ended up with a neat story to tell.

We headed down the canyon to our camp at Middle Chevron. It was situated beneath an immense cliff of basaltic lava that would be a dominant feature of the canyon for much of the remainder of our journey. We had a delightful meal of chili and cornbread with cheesecake for dessert. I laid down to sleep and watched lightning flicker in the eastern skies. The stars blazed overhead, and soon I was asleep. The trip was now "post-lava-falls". I slept soundly.

Dam engineers sure love their dam creations. The Colorado River, being the only river of note draining the Colorado Plateau, was a target of their fevered dreams, and major projects have "tamed" the river, most notably at Hoover Dam/Lake Mead, and Glen Canyon Dam/Lake Powell (above). Those who administer the giant concrete plugs love to cite the statistics: Hoover holds back 28 million acre feet, Powell 24 million, Mead is 112 miles long when full, Powell is 186 miles. It can't be denied that the concrete monsters have had a huge effect on the ecosystems of the river. Glen Canyon is entirely submerged. The river downstream runs cold all year, and surges high and low in response to electrical production needs. Native fish and flora struggle to survive in the new regime.

We were at the end of our thirteenth and starting the fourteenth day of our journey into the Great Unknown, a rafting trip down the Colorado River from Lees Ferry to Diamond Creek. I had taken an involuntary swim through Lava Falls Rapid that afternoon, but with the swim having been a far less terrifying experience than the first flip back at Crystal, I was feeling okay. Passing through Lava Falls represents to many the climax of the trip, and the last two or three days are sort of a winding down of the journey, with few large rapids.

For me though, the last two days were some of the most astounding because we had reached the site of one of the most extraordinary geological stories in the entire history of the Grand Canyon. Visitors to the main tourist areas on the north and south rims of the canyon never see the rocks that lined the canyon walls around us, and are often surprised to find they exist at all: miles and miles of basaltic lava flows!

The edge of the Colorado Plateau is punctuated by a series of north trending extensional ("normal") fault zones. They represent the boundary zone between the thick crust of the Colorado Plateau, and the thin extended crust of the Basin and Range Province that reaches across Arizona, Nevada and eastern California. When the crust stretches and breaks, pressure is released in the Earth's mantle below, allowing partial melting of the hot pliable rock. The resulting magma follows the fault zones to the surface. Between 1.8 million and just 1,300 years ago, at least 150 eruptions took place in the vicinity of the western Grand Canyon, covering 600 square miles, forming the Uinkaret Volcanic Field.

Most importantly, at least 13 of these flows spilled over the edge of the canyon and filled the canyon bottom. Vulcan, the fire god, had built his own version of Bureau of Reclamation dams. They weren't small dams. They were hundreds of feet high, and one topped out at least 2,500 feet (Glen Canyon Dam is 710 feet tall). It was the remnants of these lava flows and lava dams that surrounded us as we floated down the river. It was the first time I had seen these rocks. I was mesmerized (yes, we geologists are a strange lot).

What's even more incredible are the lakes that formed behind the dam. The largest dam formed a lake that backed the river up into Utah. If it happened today, the lava dam lake would inundate Lake Powell. It would make for a long hard rafting journey, but the rapid at the end would have been memorable...

Even more mysterious would be how the lakes met their end. It's still the subject of some research, but evidence suggests that at least five of the lava dams failed catastrophically, collapsing and ending the lake in days rather than years. What kind of evidence? The most compelling would be river deposits containing basalt boulders 115 feet across. How do you move boulders that big?

The amount of water unleashed on the lower canyon by such a failure is almost unimaginable. A modest 'fake' flood produced by releasing water from Glen Canyon Dam up the river might involve flows of 40-45,000 cubic feet per second. The largest historically recorded flood (in 1884) produced flows of about 300,000 cfs. A researcher has found evidence of a flood of 400,000 cfs around 4,000 years ago. Estimates of major floods during the Pleistocene ice ages range in the vicinity of a million cubic feet per second.

The collapse of a 1,500 foot tall lava dam may have produced a flood of 15 million cubic feet per second. That's more than 30 times larger than the biggest flood ever recorded on the Mississippi River. That's how you move 115 foot boulders.

Pictures of gigantic floods filled my imagination as we drifted past lava flow after lava flow. At first, the most vivid outcrops were the flows that had spilled over the rim in the vicinity of Lava Falls and Whitmore Wash. As we floated downstream, the basalt flows tracked along the river, forming low cliffs that went on for miles. The longest flows traveled more than sixty miles down the river bed.

In places the lava flows were thick enough to develop columnar jointing, similar to places like Devils Postpile in California or the Giant's Causeway in Ireland. The columns form when the lava flow pools and then contracts while it cools. The contraction causes the vertical fractures to develop, and they characteristically form hexagonal columns or sometimes rosettes. All in all, the day had been fascinating.

Lava wasn't the only feature of the day. At Whitmore Wash we had a chance to hike up to some interesting pictographs on a sandstone panel a few hundred feet above the river.

The view up the river was fantastic...

We camped at the very creatively named 202 Mile Camp. While I was cooking, my nephew came up to report that the bank of the river was collapsing. I wandered down to have a look and found that an underwater slide was causing large slabs of sand to be pulled towards the river, forming a large arcuate landslide scarp. After seeing a gigantic normal fault to begin the day, it was interesting to see a small-scale version of the same kind of faulting along the riverbank. The little collapsed block in the center would be called a graben.

The slide ultimately ate up a lot of the shoreline, more than 30 feet, and it was clear that a lot of sand was being lost to the deeper part of the river channel. Ever since the floodgates of Glen Canyon Dam closed in 1963, sand has been disappearing along all the shorelines of the river. There have been a few attempts to produce artificial floods that have temporarily moved sand back onto the beaches, but without the sand that is now trapped in Lake Powell, the beaches are going to continue to disappear.

At the end of the day, the moon made an appearance. It was the first we had seen of it on pretty much the entire trip. I had enjoyed seeing the Milky Way each night, and the moon would have obscured many of the stars, but it was nice to see the beautiful crescent setting over the basalt cliffs.

With the last of the twilight, I hit the sack, realizing we were down to our final two days on the river. Our takeout at Diamond Creek was only 24 miles downstream.

It was our last full day on the Colorado River through the Grand Canyon, the Great Unknown as John Wesley Powell called it in 1869. One full day, and one more night on the life-giving stream of water through one of the spectacular canyons on Earth. We had eighteen miles to go, from our camp at Mile 202 to 220 Mile Camp (it was clear that the geographers were running out of names for the features in the canyon; it's that big).

It was a day full of the best things the canyon could offer. But it was also hot. Blazing oven hot. Merciless sun beating down hot. In other words, a normal summer day in the Inner Canyon. The thing is, we had already experienced a few hot days on the trip, but not quite the kind of 115 degree days that we were warned about in the training materials. I don't actually know how hot it got, but in my memory, it was the hottest day of the trip.

They said a few things in the training videos for rafting the river. To drink before you get thirsty. To drink a gallon a day. To always wear a hat. Seek out shade when possible, and don't hike between 10 and 4. They said it takes a human body about two weeks to acclimate to extreme hot temperatures, meaning a river trip was not long enough to do so.

We were seeing all kinds of adaptations to the heat as we explored the area around our camp during the relatively cool morning hours. We had dropped nearly 2,000 feet during our two weeks on the river, and the desert vegetation was characteristic of the Lower Sonoran Life Zone (or whatever the biologists are calling it these days). Cacti had been rare in the upper reaches of the river, but now they were common.

There were a few shrubs with their characteristic waxy leaves taking advantage of the recent storms by putting out a few flowers.

Best of all were the ocotillos that we had been seeing for the last two or three days. They too had taken advantage of the recent storms, and had put out thin leaves along their green branches (most of their food production happens in the branches rather than the leaves). There were none of the beautiful red flowers (we'd need to be here in May for that).

We took advantage of the relative cool of the morning to search out some pictographs that were said to be up in 202 Mile Canyon. It took a while (which is why I had given up and photographed the plants instead), but eventually we found them. It was a small measure of the rate of geologic change that some of the blocks of rocks containing the rock paintings had tumbled down from the ledge.

Once the sun reached our boats, we set off down the river. We continued to see remnants of the lava flows that had once produced high dams, and which had continued downstream for many tens of miles (above).

We also saw another gigantic landslide that had involved the entire canyon wall (above). Lava flows aren't the only things that have produced dams on the river. As noted in an earlier post, landslides have altered the course of the river a number of times.

We saw more evidence of human occupation in the canyon. We discovered roasting pits in several of the debris fans at the mouths of some of the tributary streams. Along with the cracked and shattered rocks we found bit and pieces of pottery.

A short hot hike up Indian Canyon offered a fine view up the river. But it was hot and there was no shade. I shiver to thick how quickly I would have been in trouble here had I not been carrying a quart of water at all times. I was drinking at least a gallon and a half of water on days like this, and when it got too uncomfortable, I could splash in the river water to cool off. Despite being 200+ miles downstream from Glen Canyon Dam, the water was still in the mid-to-upper fifty degree range.

The scenery continued on a grand scale, with high cliffs at every turn. We saw another bighorn along the riverbank. It was as if the river was giving us reminders of why the canyon was precious. And that was the way I was feeling. This was the last full day, and while I was wanting to see the people I was missing in the outside world, I was also feeling like I wanted to hold onto these incredible experiences that I felt were enriching and transforming my life.

We crossed the Hurricane Fault again, and the ancient Vishnu Schist was exposed at river level once more.

In the intense sunshine, the polished surfaces of mica, quartz and feldspar reflected brightly.

It's amazing what the silt-filled water can accomplish!

As we searched for (unsuccessfully) for a shady lunch stop, we encountered an unusual looking ledge of Tapeats Sandstone on the left bank.

The top of the ledge had been scoured and eroded by river currents, and it looked recent, yet the bench was 15 or 20 feet high. It looked extremely fresh.

At the lower end, there was a strange orange-colored edifice called Pumpkin Spring. It was a warm spring deposit that was redepositing travertine that had been dissolved from the overlying limestone formations. The heat probably came from nearby active fault zones. The water was green and uninviting. The river guide suggested not drinking it because of high concentrations of arsenic (is that a poison or something?).

We set up a canopy and crowded underneath it to eat lunch. There was a hot breeze blowing so the shade barely helped. Unfortunately the wind was trying to destroy the umbrellas that most of the boats had, so there was really no place to retreat from the sun. For pretty much the first time voluntarily, I spent most of the time soaking in the river as long as I could stand it (cold!), then getting out and warming up until I was dry and hot, and then getting back in the river!

Despite the heat, we wanted to check out the unusual terrace in the Tapeats Sandstone that we had just floated by. We grabbed some water and headed back up the canyon. The edge was pockmarked with huge potholes, many of which had carved right through the rock, forming little tunnels and caves. Many of the potholes still had the pebbles and cobbles that had carved them.

It turns out the terrace has been flooded by river water in historic time during the big spring floods, but only rarely since the floodgates of Glen Canyon Dam shut in 1963. The dam is still altering the river, even 200 miles downstream.

We made one more stop that afternoon, at Three Springs Canyon. Like so many tributaries, it had a small stream of clear water that we could use for drinking. Some of the crew pumped the water filters while others hauled the five-gallon buckets down the trail to the boats.

Yours truly found he could make a human dam across the trickling creek and have a nice bath.

It was the hottest part of a very hot day, and a hot breeze was blowing up-canyon. No one felt like rowing against the wind, not in the hot sun without the umbrellas. We holed up in the shade behind a ledge at Three Springs Canyon for quite awhile, letting the afternoon shadows extend across the canyon a bit.

We arrived at our site for the night at 220 Mile Camp. As if to make some kind of point so late in our trip, it was one of the most beautiful camps of the trip. There was an island of Vishnu Schist in the river decorated with a few wispy tamarisk saplings. Our camp was in the shade (relief!), but the sun was shining brilliantly on the cliffs across the way, reflecting on the river.

The view upstream was gorgeous as well. At this late point in the day, no one else was on the river; the feeling of isolated wilderness was complete. It was strange to think that only six miles away a road reached river level, and that we would be driving out of the canyon in the morning.

We drank the last of the beers and the sodas, ate most of the remaining food, and sat in the warm air watching the sunlight drain away from the cliffs as night fell. After a while, a cool breeze wafted off the surface of the water.

The moon was a touch higher in the sky than the previous evening (it always happens that way), but it soon dipped below the cliffs. It was the 11th of August and the Perseids Meteor Shower was scheduled to debut in the night sky. It did not disappoint; as we talked and sang and played the guitar, I counted maybe a hundred shooting stars, some of them blazing a trail all the way across the sky. I had been turning in early on many nights of the trip, but on this night I was still awake staring at the show in the sky until well past midnight. I'll not forget it any time soon. I didn't want the night to end, and yet I did.

Tomorrow we would be back into civilization, and I would be starting the journey home...

Elegy (from the Greek word for "lament") is a mournful, melancholic or plaintive poem, especially a funeral song or a lament for the dead.

How many ways can I describe the last day of our trip? The word "elegy" came to mind. It was the end of a long but incredible rafting trip down the Colorado River, and I was feeling sad. Sure, I was anxious to hear the news from the family and the outside world, but it was also the ending of one of the greatest experiences of my life. It was the ending of a personal journey, which ventured sometimes into terrifying darkness, but mostly it was a world of sublime beauty, even glory. And... the story was about the abuse and destruction of a river.

We packed at a leisurely pace. We only had a few miles to go, and the Hualapai Nation requested that no take-outs happen before 10 AM.

We set out down the river. We turned a corner and I saw something I hadn't seen in more than a week: a familiar sight. I've been down Diamond Creek several times, and Diamond Peak has an unmistakeable shape, even from the opposite side. To offer a sense of scale, Diamond Peak is only about 200 feet higher than the beach at the beginning of our trip in Lee's Ferry. It stands out in part because it is a fault block that has risen between two fault zones. Erosion along these faults has led to the trick of the topography that allowed a road to be constructed down to the river.

At mile 224 we passed the final rapid, a little riffle that didn't even merit a name. But it was the last one...

And then we entered the last mile or so of river, and it nearly broke my heart. It was perfect. In that moment I wanted to simply float on and on into eternity. Pete stopped rowing and we simply drifted. The river was quiet. A swallowtail butterfly landed briefly on my hand, confused by the bright colors of our clothing and luggage. Pete pulled out his harmonica and played a few tunes.

I wrote in my journal...

I was suddenly wistful, wishing to float down a serene river, at peace, but knowing that it is never truly serene. There are those perfect moments that make everything worthwhile but around the bend there can be excitement, action, and even terror. But peace returns, and we recover our sense of well being.

Such beauty in such a savage land. Without the river, life would be barely possible for a person. Too far between water sources when it is so god-awful hot. The hike yesterday across the Tapeats ledges could have been unbearable without soaking in the cold water first.

But along the string of life-giving water, the beauty is overwhelming. Every side canyon would be worthy of a national park all its own. I found myself thinking 30 Yosemite Valleys strung in a line would equal the Grand Canyon.

I don't know that I will be back. I faced the big waters twice and made it through, one time in terror, and the other less so. But I enjoyed the rapids a bit less afterwards...

...but nothing can take the place of drifting down the placid parts of the river; seeing the herons and bighorns, and I'll never forget the sounds of the canyon wrens. I would do it for that...those parts will always live on in my memories.

The cliffs would glow red in the pre-morning hours after the stars disappear. The red fades into shadow, and then the sun lights up the cliffs in blazing orange. The river was always brown but in the shadows of evening and morning, it reflected the lights of the cliffs above...wonderful moments.

I took one last video as we drifted...

And then, a strange sight, a big orange ball and a cable strung across the river. It was the gaging station at Diamond Creek. It was a reminder that this was a heavily utilized river that had to be measured and controlled. There was a feeling on the entire trip that the river we were traveling on was not "right". It was far too cold for a desert summer, and it ran too high for any snow-fed river in August. The disappearing beaches demonstrated that the river rarely flooded anymore.

It's hard to imagine the difference between this river and the river that was experienced by John Wesley Powell and his courageous men. And it was almost entirely due to the construction in 1963 of the monstrosity that flooded a precious gorge called Glen Canyon. And the sewage lagoon that formed behind the dam was named for Powell. I don't think he would have been pleased. He recognized sooner than most the problems that would lie ahead for the millions who would come to depend on an inherently undependable river. The lake that bears Powell's name may never again fill if the predictions of the climate scientists come to pass.

The river will return. And it probably won't take as long as it did when lava flows temporarily stopped the flows of the river. The dam is built in unstable porous rock, and it almost failed catastrophically in 1983, due in part to the arrogance of the dam engineers. It ultimately must fail, probably within a few years of being abandoned by the society that maintains it. Ultimately the river will return to something of its former self. Time is all it needs.

The gaging station also meant that our time was almost up...

A beach came into view, with trucks and giant pontoon boats. We waited until the other boats left on their journey to Lake Mead and pulled off the river for the last time.

Rigging the boats at the beginning of our trip took parts of two days. The de-rigging took an hour or less. No one wanted to hang out on the river in the growing heat of the day.

All of the material we began the trip with came off the river, although some of it had been, um, "transformed". A few items, most notably my hat, gloves and a guidebook were still in the river somewhere. Oh and a tent that blew away several days earlier.

I finally had a look at the unadorned raft that had been my home for the last two weeks. We developed a luggage line and got all our gear onto the truck; we would unscramble it in much more comfortable weather in Flagstaff at an elevation of 7,000 feet. We piled into the truck and a van and set out on the bumpy 20 mile drive to Peach Springs where we would rediscover ice cream and flush toilets. A 90 mile drive to Flagstaff followed...

...our trip was over.

I hope you have enjoyed following our journey. Thanks to all those who traveled with me, and especially my brother and his family who invited me to come along. Thanks to Pete, who was a wonderful boatman and traveling companion. They were wonderful people to travel with! Thanks to Barry, Bev and Jeff, who pulled me from the river, sometimes more than once. And thanks to all the river runners who have clearly worked to keep the river clean and wild.

Look for one more post in this series, a compilation of all the posts on the journey, and maybe a few final thoughts.

There are lots of volcanoes in California, in the deserts, the eastern Sierra Nevada, even in the Coast Ranges, but the most recent and most diverse volcanoes are in the north state, in the Cascades Range and the Modoc Plateau. I'm headed up there tomorrow with my students.

We are spending our time in Lava Beds National Monument which sits on the flank of California's biggest volcano (surprise! It's not Mt. Shasta...or Lassen Peak either).

We'll have a look at Mt. Shasta, which is the tallest volcano in California, and probably the biggest stratovolcano in the Cascades...

We'll finish our studies at Lassen Volcanic National Park, site of the last eruption in California, in 1914-17. With a bit of luck maybe a small cinder cone will erupt harmlessly somewhere near us along the way! Geotripper will return in a few days...

It's always hectic in the week or two after a major field trip, and this week is no exception, so it's a bit more difficult to post detailed explanations. I want to spend some time exploring the Cascades with you all, but for now, how about a short collection of photographs so you can see the kind of trip we had? We did a loop through the Cascades Range and Modoc Plateau of Northern California. Along the way we saw world class examples of practically every kind of volcanic feature there is.

Above is Mt. Shasta and Shastina, a huge composite cone that dominates the scenery of the north state. The mountain tops out at 14,162 feet, and is still considered quite active with eruptions as recently as 1786.

We spent much of our time at Lava Beds National Monument, a lesser-known park near the Oregon border south of Klamath Falls. It is a fascinating region to explore. It is on the flank of Medicine Lake Highland, a huge shield complex, and it offers marvelous vistas.

Besides the numerous excellent examples of cinder cones and lava flows, it has around 700 lava tubes with something like 75 miles of passageways. The picture below is a shot of Valentine Cave, one of the most accessible of the lava tubes. These tubes are the main plumbing system of basaltic lava flows, and as the eruptions ended, the tubes drained.

We spent a night at beautiful McArthur Burney Falls State Park. An explanation of the falls will be forthcoming in a later post.

Our last exploration was Lassen Volcanic National Park, where we had a chance to explore the largest plug dome on the planet. The park also has some interesting geothermal areas, expecially Bumpass Hell.

We had a great time!

As many of you know, I recently ended a rafting trip down the Colorado River through the Grand Canyon. I just finished a blog series on the journey, and what I've done here is to list the posts in their original order, so that if you want to catch the whole story in one place, this is where you want to start!

Rafting the Colorado River: This is the original post in the series, explaining how I got there, and what I was feeling about a journey that I waited forty years to complete.

Everything you wanted to know about rafting on the Grand Canyon but were afraid to ask: A description of what's involved in a 16 day journey on a river with no stores, bathrooms or trashcans.

Cloudburst (x2)! And Off We Go: Two intense thunderstorms give us a muddy sendoff down the river. Page and other towns got pounded that week by flooding.

Passing through the Permian Period: Our first day on the river takes us through the upper layers of the Grand Canyon, the Permian-aged Kaibab, Toroweap, Coconino and Hermit formations.

Whodunnit? A Mountain Range Goes Missing: The Hermit Formation and Supai Group provide evidence of the existence of a long-eroded mountain in southwest Colorado. And I row a raft for the first time!

Visions of Paradise and a Bug's Horror: We enter Marble Canyon, dominated by the beautiful cliffs and caverns of the Redwall Limestone. A beetle has a tough day.

Exploring 300 million year old and 50 year old caves (and some fossil hunting): We explore Nautiloid Canyon and an exhumed Paleozoic cavern. We also see evidence of a bone-headed plan to dam Marble Canyon. It would have been an unspeakable crime...

Looking for the Rivers within the Rivers of Marble Canyon: The Devonian Period is represented only by the Temple Butte Formation and the exposures are discontinuous because they were originally only the fill within eroded stream valleys. Plus a cool side trip to a small waterfall.

We interrupt this scenery for a very recent flash flood and a biological disaster: The cloudbursts we experienced a few days earlier caused some flooding in the side canyons. And a look at the tamarisk tree, an invasive species.

Catching an Iconic Scene in the Grand Canyon, and a Bi-Colored River: The small Ancestral Puebloan granaries above Nankoweap Canyon are one of the more famous sights on the river, but oh, what a climb! And floodwaters in the Little Colorado change the color of the main river.

Living in a Thomas Moran Painting, and Through a Canyon Storm: A passing storm gives the canyon a dreamy impressionistic look. I get my favorite picture, and I don't get overly wet; there were too many gigantic boulders to cower under.

In the depths of the Grand Canyon there are three more Grand Canyons...Checking out the Supergroup: There is around 12,000 feet of ancient sediments and volcanic intrusions tucked in the deepest parts of the canyon, and they are only accessible by river or long hot hikes. We give them a look.

Journeying to my Roots, and to the Roots of Mountains: We reach some of the monster rapids, including Hance. It was here in 1976 that I was becoming a geology major on my very first field studies class. Who is that gawky thin kid?

Exploring the Heart of a Long-Gone Mountain Range (and words from home): In the bottom of the Grand Canyon there are the roots of a huge mountain range that formed before complex life even existed on our planet. And I hear words from home for the first time in week.

We Run the Big Rapids, Sometimes in Rafts: We run three of the biggest rapids on the Colorado River. I experience something I haven't felt in a long time: terror. We flipped on the biggest rapid and I took a long cold swim through the 10-foot waves and the Rock Garden.

The Aftermath of Chaos...Finding Beauty in the Oldest Rocks of Grand Canyon: The Granite Gorge was a terror-filled place for John Wesley Powell and his men in 1869, but for me on a day after the rapids disaster it was a beautiful place.

The Hidden Places and Putting a Hand Across 1.2 Billion Years: Every side canyon in the Grand Canyon holds a treasure. We visited two, the Elve's Chasm and Blacktail Canyon, and we laid our hands across 1.2 billion years at the Great Unconformity. We also met with a herd of bighorn sheep.

Crossing the Great Unconformity Again...But Which One? There are really two major unconformities in the depths of the canyon (and more than a dozen more minor ones). We got a glimpse of the angular unconformity, and explored the billion year old sills, intrusions of basaltic rock that lined the canyon for a few miles.

A Gigantic Failure Produces One of the Most Beautiful Sights in the Grand Canyon: Slope failure and landslides had as much to do with the formation of the Grand Canyon as the Colorado River. At Deer Creek, a landslide produced one of the most beautiful canyons and waterfalls in the entire canyon.

Mad Cats and Amoebas? Trying to Keep Names Straight in the Grand Canyon: Not many people saw this post for some reason, but Matkatamiba Canyon is one of the prettier side canyons on the river, and one of the favorites of the veterans of previous river trips.

"Disaster" in National Canyon, and the Volcanoes of Grand Canyon: An unbelievable flood last year, and an unbelievable amount of basalt lava in Grand Canyon. And just like that we are facing Lava Falls, the single worst rapid on the river, in turbulence if not length.

Zero Hour at Lava Falls: A story of courage, redemption and the triumph of the human spirit? No. I tried to ride Lava Falls in a raft, but had to swim instead. Involuntarily. See the video version!

Vulcan the fire god says "You call that little piece of concrete a dam?: Lava dams in the Grand Canyon may have stood 2,000 feet high, and may have backed up dams for three hundred miles or more upstream.

Heat...and All Things Beautiful: It was post-Lava Falls, and one of the hottest days we had on the river. And the beauty surrounded us, in the water, in the cliffs, and in the animals.

The Last Day...An Elegy for a Journey, and for a River: I didn't want to leave. The last two miles on the river were the most precious of all, drifting slowly in the current. And then it was over. We derigged and made our ways to our homes, and the Colorado just rolled on.

Yeah, it might be your park, but Republican leaders are throwing a tantrum. You shall not pass.

It's funny how the little things can be so irritating. Because of the government shutdown, I cannot take my students on a field studies class to one of the more stunning places in our country, Sequoia National Park. As a result, the communities near the park will not receive our business, and we will be traveling someplace else.

Irritating yes, but nothing like the uncertainty that our public servants, the park rangers, the FBI agents, the food inspectors, the diplomats, the people who are doing the necessary and important business of our country have to suffer at the hands of fools. So yes, this post is uncharacteristically angry, because I am very angry.

Congressional Republicans are a bunch of spoiled children conducting a public tantrum that is hurting millions of people. But don't expect them to ever understand that. They collectively seem incapable of empathy. And yes, in this description I am including my own representative, Jeff Denham.

I was taught civics and politics in high school. Elected representatives go to Washington and enact laws using specific processes that have served us well for more than 200 years. If political parties didn't like laws, they could be repealed. By a proper vote in both houses of Congress, and with the signature of the President. Usually we expect that our elected representatives understand how the political process works.

The Affordable Care Act will benefit millions of people. We've already let too many people die or go bankrupt because of health catastrophes in the absence of health insurance. We've been abused for years by health insurance companies acting as the dreaded "death panels" that Republicans keep trying to scare us with. The ACA will (and already has) provided coverage for millions without the caps and limits on pre-existing conditions. And millions will now pay less for health care. The law was passed by the duly elected members of Congress, and signed by the president. It was upheld by the Supreme Court, including the conservative Justice Roberts. It is the law of the land.

But because the spoiled children who pass as representatives of the Republican Party don't think that my children and my cousins and millions of others deserve health care, they've shut down the government, tossing hundreds of thousands out of work, and causing children and the elderly to go hungry. They've endangered all of us. All because they don't truly believe in democracy. The law was enacted. There was an election in which health care was a main issue. And they lost. Get over it, and get our country back to work. Extortion is ugly and morally wrong.

Comment if you wish, but this isn't a debate forum. Intelligent and well-considered objections only. If you decide to unthinkingly parrot Republican talking points, don't expect them last very long in the comments section.

Thanks to the obstructionist party in the House of Representatives, we've had to completely retool our last overnight field studies trip of 2013. We had planned to explore Sequoia and Kings Canyon, but with the absolutely wrong-minded shutdown of the federal government, those parks are closed.

Luckily, even though the state of California flirted with the idea of closing her state parks, they are open for business, so we will be exploring one of the greatest stretches of coastlines in the world, the one between Big Sur and Bodega Bay. There just isn't any place like it anywhere.

It's been a while (like never) that I've had to plan and conduct a three day trip with three day's notice. I started from scratch, but I think we've got an ambitious itinerary that is flexible, and bound to be fascinating no matter where we go.

I will let you know how it worked out in a few days!

In the meantime, contact your representative and tell them to stop holding the government hostage. The fools in Washington have officially failed basic civics and political science. You don't get your way by tossing hundreds of thousands out of work, and taking food from children and the elderly (including the veterans).

We were off studying the geology of the California coastline between Big Sur and Bodega Bay this weekend, but just like always, furry and feathery things provided distractions. I thought I'd get these pictures up first so I can go back to the geology discoveries we made later.

Seeing an otter on land was a first for me. I knew they were perfectly capable of being out of the water, but I'm not on the coast all that much. The one above was on the granitic rocks of the Salinian Block at Point Lobos State Reserve, in one of the coves near Bird Island.

The Southern Sea Otters were hunted nearly to extinction in the 1800s, and were thought to be entirely gone until a colony of fifty or so were discovered near Bixby Bridge in Big Sur in 1938. There are nearly 3,000 of them today along the central California coast.

The second otter was doing normal otter things in the water. They may be deadly serious at whatever they are doing, but watching them spin and wrap themselves in seaweed sure looks like play to me. The otters help to keep the kelp healthy by preying on the sea urchins that tend to destroy it. Of course they also eat other foods more valuable to fishermen, so there is some tension caused by their population growth.

The pelican is another animal that is deadly serious at whatever it is doing and yet can't help but look clownish in some way. They are so ungainly looking, right up until they starting flying and soaring over the water. Then they are one of the most graceful creatures in existence. These pelicans were on Bird Island at Point Lobos.

We thought we were too early to see the migration of the Gray Whales, so we were surprised to see spouting off in the distance, and hit the brakes just south of Carmel and Point Lobos to see who was out there. I don't think they were Gray Whales, but what were they? I don't know if these pictures provide enough clues for you veteran whale watchers, but if you can identify the three whales that were traveling close to each other, let me know!

When you've been to a place a few times, it becomes possible to concentrate on the subtle changes that can happen at different parts of the day and under changing weather conditions. We arrived at Lava Beds National Monument on our recent field studies journey to the Cascades volcanoes of northern California ahead of the first storm of the season. I wandered out into the lava flows and took in the scene. I was remembering the events here that led to the destruction of a culture more than 140 years ago.

The gathering clouds could have been worrisome since we were camping out, but the park staff had generously allowed us to make use of the research center, so we had a warm dry place to retreat to at the end of the day. The rain fell all night, and when the morning arrived, the valley was filled with an ethereal mist. The land was barren and lonely. It was hard to imagine this valley as a home, but for centuries it was indeed home for bands of Native Americans, including the Modoc people.

Their presence could be felt in many ways. Our first stop was at Petroglyph Point in an outlier of the Park near the town of Tulelake. The lake once filled most of the valley, and waves used to break at the base of the cliff. The unusual looking rocks are the insides of a tuff cone, a volcanic edifice that formed during a mildly explosive eruption about 270,000 years ago.

Several thousand years ago, the people who lived here took canoes and made their way to what was then an island in the midst of the large lake. There they carved numerous petroglyphs, more than 5,000 of them, making this outcrop one of the largest petroglyph panels in the United States

The soft tuff was easy to carve, but the softness will be the undoing of these precious marks of the past. The water that filled the lake 140 years ago has been diverted and most of the lake has dried up. Wind now carries sand that blasts against the edge of the cliff, slowly eating away the enigmatic symbols.

And there is an even more horrible problem. Fifty of the petroglyphs were vandalized last year, leading to a closure of part of the panel. These are sick people who would do such things.

After leaving Petroglyph Point, we arrived at the epicenter of the battleground where the Modoc People lost their homeland and much of their culture. They put up a hell of a fight against impossible odds.

The following is an excerpt of an earlier post I wrote about the saga of the Modoc People:

The Modoc people had lived in the Klamath Falls-Tule Lake region from time unremembered, and made first contact with Europeans in the 1840's as settlers arrived on the Oregon Trail. Relations between the cultures were rocky and sometimes violent, and eventually the Modoc people were forced to move to the reservation of their ancestral enemies, the Klamath people. After several years of intolerable conditions of neglect, some of the Modocs left the reservation and returned to their homeland on the Lost River near Lava Beds, led by Kientpuash, known to the settlers as Captain Jack.

The hostilities began on November 29, 1872. On that day, the U.S. Army tried to round up the Modocs at their Lost River encampment, north of Lava Beds, in order to return them to a reservation in southern Oregon. Shots were fired, both sides suffered injuries, and the Modoc people fled south, led by Kientpuash. A separate party, led by Hooker Jim, went on a rampage, killing 14 settlers. The bands made their way by canoe and horse to the site that came to be known as Captain Jack’s Stronghold. The band included 53 men of fighting age, and about a hundred women, children and aged Modocs.

The Stronghold was the site of two major battles and a long siege by U.S. troops and militia of the small band of Modoc peoples during the long winter.

The conflicts that took place on this barren surface reveal much about the need to take into account the geology and geography of the battlefield. Although outnumbered at least ten to one, the Modoc warriors were able to take advantage of the landscape to execute their defense, and in the two major battles that took place, they inflicted many casualties on their opponents while suffering very few among themselves. During the January 17, 1873 conflict, the attacking army did not kill or injure a single Modoc warrior while suffering 37 casualties, including 9 dead.

The Modocs could hardly have chosen a better spot to make their stand. The trail through the stronghold reveals a series of schollendomes (pressure ridges) and scarps that almost completely encircled the Modoc encampment. The fractures and fissures along the tops of the schollendomes were natural trenches that allowed quick access to any point along the defensive perimeter, and the Modocs had an excellent view of the flat open landscape that the U.S. Army had to cross in order to attack. In addition to defensibility, the stronghold included access to water and food along the shoreline of Tule Lake, a natural corral where cattle could be kept, and lava tube openings that provided shelter for the Modoc families.

Another advantage of the site was the presence of an escape route. After suffering a long siege and cold winter, the Modoc people prepared for another assault by the Army, now numbering more than 700. On April 11, during a peace parley, the Modocs shot and killed General E.R.S. Canby, in the hopes that by killing the Army’s leader, the soldiers would go away. The opposite occurred, and on April 15 the Army forces began bombarding the stronghold and advancing past the outer perimeter of the Modoc lines. After two days of attack, with 6 dead and 17 wounded, the Army poured into the stronghold to find…no one. On the night of April 16, the entire Modoc party, 160 men, women and children, along with dogs and horses, had deserted the stronghold, moving south along a smooth area of the lava flow, only a few hundred meters from some of the Army encampments.

Despite their successful escape, the Modoc people were now caught in the open, and it was only a matter of time before they were captured. Within a few weeks, Hooker Jim betrayed Captain Jack’s location in return for amnesty. Ultimately the Modoc people were moved to Oklahoma, and Captain Jack, along with three others, was hanged. The last major conflict in California between the U.S. Army and the aboriginal peoples was over. As the park brochure notes: “The cultural identity of an entire people was lost here…so settlers could graze a few cows”

About 200 Modocs remain in Oklahoma, descendants of seven of the survivors of the war, and about 500 Modocs still live in Oregon. The Modoc people returned to Lava Beds in 1990 for the first time in 117 years to perform ceremonies on their ancestral lands, and now do so yearly.

At least when the Republicans come to their senses and reopen the government. The park is closed right now.

Lava Beds National Monument was one of the central locales for our exploration of the northern California Cascades on our recent field studies class. The park was established on the northern flank of Medicine Lake Highland, a shield-like edifice that is the most voluminous volcano in California (about 130 cubic miles of lava as compared to 108 at Mt. Shasta). The park is known primarily for the richness and variety of its lava tubes, and for being the ancestral homeland of the Modoc People, who fought against impossible odds for the right to live on the land in 1872 and 1873. They lost everything.

Lava Beds is also one of the best places I know of outside of Hawaii to see the classic features of basaltic lava flows. The park preserves a number of extensive flows, some as young as 1,150 years. In the dry high desert environment, they look as if they erupted yesterday.

We drove up the park road from Captain Jack's Stronghold and found a marvelous example of an a'a lava at the Devil's Homestead flow, which erupted about 12,000 years ago (above). I was trying to imagine crossing the lava flow barefoot, saying "ah, ah" the whole way. Basalt is often quite liquid (non-viscous), but with distance and dropping of temperature, the lava can crust over and break up into a blocky rough surface.

A short distance later we encountered one of the youngest flows in the park, the Black Crater flow, dated to about 1,250 years ago. The short trail to the spatter cone crosses some excellent examples of pahoehoe flows, formed by basalts that had low viscosity .

Black Crater is actually quite colorful. It is not really a crater at all, but is instead a group of spatter cones, which formed as lava droplets popped out of the vents, forming small cones of popcorn shaped basalt.

A bit further up the road we found the Fleener Chimneys, a group of spatter cones that were the source of the large Devil's Homestead flow, seen in the first picture. The Dragon's Mouth is a small lava tube opening that provides a clue of how basalt lavas can flow for many miles. They crust over into well-insulated channels.

There are nicely developed spatter cones at the Chimneys, that like the other features we'd seen, looked as if they erupted practically yesterday instead of 12,000 years ago.

The pahoehoe flows seem to still retain a glassy veneer, a feature that is quickly lost in more humid environments.

Three vents from the Devil's Homestead flow can still be seen (the "chimneys"). One was originally 50 feet deep. Morons over the years kept throwing rocks in the hole, filling it. Volunteers recently pulled 35 TONS of rocks from this particular chimney. Looking down the vent made me think of the Sarlaac in Star Wars...

Our next stop was our first exploration of the lava tube system. The 3/4 mile stroll to Big Painted Cave offered an excellent view of Schonchin Butte, a classic cinder cone, one of many scattered across the flanks of Medicine Lake Highland.

Up next...going underground in Lava Beds!

Lava Beds National Monument is a special place, one of my favorite spots to visit in California. It's so different than what people expect of a California park: where are the beaches, the mountains, the Redwood trees? It's way out in the hinterlands of northeastern California, about 30 miles south of Klamath Falls, Oregon. In the previous two posts, we mentioned the historical value of the park as a monument to the memory of the Modoc People, and as a great place to see basalt flows. But one of the other big reasons the monument was established can be seen in the picture below.

What? You don't see anything except piles of boulders? They actually actually reveal a bit of the inside of a volcanic system. Not the really deep stuff, but the plumbing system that allowed molten basalt to flow many miles without solidifying. The picture below is of a collapsed lava tube system. The park has many others that haven't yet collapsed.

Lava Beds has a startlingly large number and variety of lava tubes. In a small park, perhaps no wider than a dozen miles at any point, there are more than 700 individual caves with something like 75 miles of passageways. And a large number of them are open and accessible for exploration.

We paid a visit to four of them during our teaching day, and the students visited another half dozen in the evening after the academic day was done (it doesn't really matter in a cave whether it is day or night, after all). We hiked first to Symbol Bridge Cave, a short cave on the main Mammoth Crater lava flow system. The tube, which is collapsed in many areas, is around 12 miles long, extending across the park. Modocs or other Native Americans left pictographs on large basalt boulders at the entrance.

Big Painted Cave is just a short distance away on the same tube system. It also has some pictographs (hence the name), but in the bottom it also has an interesting sight: an ice pool, down inside a second level. Open water of any kind is rare in the park. Basalt flows tend to fracture while cooling, so water tends to seep into the ground and disappear, later emerging from large springs around the margins of the volcano (Medicine Lake Highland). If you have a plastic water bottle next to you, you probably are drinking some of the volcanic water from MLH. They bottle it and sell it.

In some rare instances, the fractures are blocked and water accumulates in the bottom of the cave. During the winter, cold sinking air freezes the water, and the cold air remains in the bottom of the cave all through the summer. The ice persists all year.

Our next exploration took us to Skull Cave, the largest cave opening in the park, at about 60 feet high and 60 feet wide. It somehow feels bigger as you walk into the darkness. It also has a sinister aspect, one that earned the cave's name. Just at the point where the darkness becomes complete, the cave drops off into a deeper chamber, a fall of about 20 or 30 feet. Numerous bones were discovered there, including those of two humans. Luckily, today there is a trail and metal ladders that avoid the dangerous drop-off. There is a large ice pool in the depths of Skull Cave as well.

Somehow I keep mentioning Star Wars things; in the last post in was a Sarlaac. In this one, I couldn't help but feel like I was walking through the belly of the giant worm cave in the asteroid field of "The Empire Strikes Back", where the Exogorth lived.

Our next stop was Valentine Cave. It is different than the others. The majority of caves in the park are part of the Mammoth Crater Flow, which emerged around 30,000 years ago. Valentine's flow (called the Valentine flow, by incredible coincidence), erupted only about 11,000 years ago. The cavern passages have far fewer collapsed sections, and many of the collapse blocks that were in the cave were removed by the CCC during the Depression years. The cave is clean and easy to stroll through.

Many typical lava tube features can be viewed in the passages, which total around 1,600 feet. They include terraces and benches that represent the drop in the flow level during the waning stages of the eruption. The ceilings are covered with thousands of lavacicles, where lava was dripping from the roof of the tubes. They make a good argument for wearing helmets whenever exploring the caves. The spiky rocks can put a real dent in someone's skull.

Lava tubes, like all caves, can be notoriously hard to photograph. The dark basalt tends to absorb light. Camera flashes wash out the scenes and leave no shadows to provide depth. I experimented with time exposures to varying success, using my flashlight to paint the walls. The white material is sodium bicarbonate and soluble salts that have seeped through the fractures from the ground above. One can see the popcorn-like surface of the last lava to flow through the tube.

I was happiest with the shot below. It shows best the three dimensional aspect the cave.

The caves of Lava Beds are fascinating. Some provide micro-climates where ferns and other unusual biota survive, despite aridity of the high desert environment. Others are full of ice (and are so fragile that tours are only offered in winter, since the warmth of people can cause melting). Quite a few have multiple levels, as one lava flow followed another. Post Office Cave has at least five of these levels, and Skull Cave has three. A large number of animals and insects live in the caves, including several endangered bat species (all bat species in the country are endangered by White-Nose Syndrome, which is spreading west from caves back east).

The park service has provided a pleasant campsite among the juniper trees, and a newly constructed visitor center. They sell cheap bump hats, and loan out flashlights for visitors to explore caves.

We emerged from Valentine Cave, and returned to our base at the Research Center. Tomorrow we would be going over Medicine Lake Highland.

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Into the Great Unknown: Crossing the Great Unconformity Again; But Which One?

Into the Great Unknown: A Gigantic Failure Produces One of the Most Beautiful Sights in the Grand Canyon

Into the Great Unknown: Mad Cats and Amoebas? Trying to Keep Names Straight in the Grandest Canyon

Into the Great Unknown: "Disaster" in National Canyon and the Volcanoes of Grand Canyon

Into the Great Unknown: Zero Hour at Lava Falls Rapid

Into the Great Unknown: Vulcan the Fire God says "You Call That Little Piece of Concrete a Dam?"

Into the Great Unknown: Heat...and All Things Beautiful

Into the Great Unknown: The Last Day...An Elegy for a Journey, and for a River

Hitting the Road: California's Volcanic Lands

Exploring the Cascades: Home from the Road

Into the Great Unknown: A Journey Down the Colorado River Through the Grand Canyon (a compilation)

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Want to see classic volcano features in California? Check out Lava Beds National Monument...

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